Micrometer-calipers



UNITED STATES PATENT OFFICE.

GEORGE F. STILLMAN, OF MADISON, VISCONSIN.

MlCROMETER-CALIPERS.

SPECIFICATION forming part of Letters Patent No. 279,038, dated `June 5, 1883.

Application filed January 30, 1883. (Nobmodel.)

To all whom it may concern.;

Be it known that I, GEORGE F. STILLMAN, of Madison, in the county of Dane and State of Visconsin, have invented certain new and useful Improvements in Micrometer-Calipers; and I do hereby declare that the following is a full, clear, and exact description ofthe invention, which will enable others skilled in the art to which it appertainsto make and use the same, reference being had to the accompanying drawings, which form a part of this specification, and in which- Figure l is a sectional view of my improved calipers. Fig. 2 is a sectionalview, on an enlarged scale, of the micrometer-screw with the sleeve or socket in which it works and its index-piece detached from the bow; and Fig. 3 is a sectional detail view of the sleeve and nut with the screw removed.

, Like letters of reference indicate corresponding parts in all the figures.

My invention relates to calipers, or instruments for ascertaining the exact dimensions of bodies; and it consists in the construction and combination of parts, as hereinafter more fully described, of micrometer-calipers in two' separable parts-viz., the micrometer-screw and its adj uncts, and the bow 7--whereby the same measuring-screw may be appliedto bows varying greatly7 in size or span thereby greatly increasing the capacity of the instrument without adding materially to its cost.

My improved micrometer-calipers consists of anely-threaded screw, A,which has a head, B, and works in a sleeve, C, the lower part of which forms an internally and externally threaded nut, O, provided with a milled flange, D. Upon the outside of sleeve C, above ange D, is marked off a scale, o, and the upper smooth part or stem of screw A is provided with an index-piece, G, which is in the nature of a tube depending from the head and encircling the upper smooth part of the screw. rlhe lower end of this tube is beveled, as shown at g, and may be marked with a scale by which,

in conjunction with the scale marked off on sleeve C, the exact adjustment of the screw is indicated.

E is the bow, which has an adjusting-screw, F, working in a threaded socket at the lower end of the bow, which is in a line with a threaded socket, H, at the other end of the bow, into which nut C is screwed. Thus it is obvious that bows of various size or span may be used provided their sockets H are of even size, so that the screw,with its nut and socket, may be shifted from one bow to another, as occasion may require, according to the size of the objects on which it is to be used. In Fig. l of the drawings I-have shown two different sizes of bows, E and E', with their respective adjusting-screws, F and F, both adapted for use with the same micrometer-screw.

Having thus described my invention,.I claim and desire-to secure by Letters Patent of the United States l. The combination, in calipers, of the bow with its adjusting-screw and threaded socket lH opposite thereto and in a line therewith,

detachable sleeve C, having index o, and provided with the nut C, having flange D, and

screw A, having head B, and tubular indexpiece G, substantially as and for the purpose herein shown and set forth.

2. In micrometer-calipers, the combination of the screw A, having head B, and tubular index-piece G, with the detachable sleeve C, screw-threaded inside for the reception of screw A, and having scale c, milled ilange D, and lower screw-threaded end, C', adapted to be detachably inserted in a screw-threaded socket in one ofthe arms of a caliper-bow, as

and for the purpose shown and set forth.

. In testimony that I claim the foregoing as my own I have hereunto affixed my signature in presence of two witnesses.

GEORGE FREDERICK STIIJLMAN.

Vitnesses:

J. F. REILY, `NM. SEOHER. 

